Folic acid during pregnancy to eat 0.8mg or 0.4mg depends on the specific situation of the pregnant woman, folic acid metabolism force and so on. Folic acid is mainly used for various causes of folic acid deficiency and folic acid deficiency caused by megaloblastic anemia, pregnancy, lactating women preventive administration; chronic hemolytic anemia caused by folic acid deficiency. If you are taking folic acid to prepare for pregnancy, it is normally recommended that you choose folic acid tablets with a specification of 0.4mg and take one tablet once a day. For older pregnant women, women who have a history of poor fertility or who are at high risk for folic acid genetic testing, it is usually necessary to double the supplementation, and the doctor will recommend taking folic acid tablets with a size of 0.8mg. Patients are advised to take folic acid tablets under the guidance of a doctor and not to use them privately.